Gyroscopes



. Feb. 10, 1959 v A. BROWN ETAL 2,872,822

' GYROSCOPES 7 Filed Nov. 22, 1957 4 Sheets-Sheet 1 I i I i INVENTDES JACK A4 BROWN Egwmzu H. N.WATSON Feb. 10, 1959 J. A. BROWN ET AL 2,872,822

GYROSCOPES 4 Sheets-Sheet 4 Filed Nov. 22, 1957 Fla. 4.

lNvEN'mRS JACK A. BROWN EDWARD H. N. WATSON United States (Jlairns priority, application Great Britain November 26; 1 956;: e

11 creams, lye-5.1g

Thi nt on ela es to syr seer s a t i -e ses aes wi h pr vi in a l Z PI YQd .m e li s! for. nnin yrosc pe roto up to speed w. a s rs el rin is. 1 t? erect. Th yroscope ma fo mp e eume v missile pr other cr f wh ch a t r fir n r else-e 1 rs l ses the gyroscope o .wntrol its path- T e syreseese r tor will normally be sta onar pr r o fi n 9 ak but when the moment of la glrlching approaches the gyro; scope must be erected and the rotor be run uickly up .to speed. Moreoyer, whateyer member or means is pplied to the rotor to spin i p to s eed mu t the be withdrawn clear of t e simba operatin spa e is allow the yros op to ina i n prope ly he l neesed- Aeeording to sh Pr s l 'iasen io mec n sm t spinning" 's ntbalins aat d yr seop :o .o eqm r see a spindle which is capable of .beingadvauced into coaxial engagement with the rotor so as to be coupled coaxially thereto,'means for rotating the spindle when so coupled to spin the rotor, and retracting means for automatically retracting the spindle clear of the'gimbal ring operating the space when the rotor has been-run up'tospeed.

The present invention provides a mechanism for spinning a gyroscope rotor which may inicestain circumstances be made very light and compact, and yal rich moreover has the advantage that the very considerable accelera-ting (torque is applied gcoaxiaily .to the rotor by the coaxial spindle and .so does not giye'rise ,to heavy loading of .the rotolr hearings due to torque reaction.

' Convenientlylthe spindle may he reles'copic, one end portion iheing" capable or being extended telescopically from "the other end portion into coupling engagement with the rotor and of'=being retractedtelescopically :hy the retracting means. r a

' aiiouslniechanisms may .be (employed for causing the rotation of the spindle, for exannrlelthere maytbe provided ailead screw coupled to the'spindle, ,or constituted by .a part Qo-fit; and-formed with .a' quick ,s'crewthread, .a correspondingly screwthreacled jdriving nut threaded Ion .to the lead screw and prevented from rotating aboutnit's axis, and piston means for driving the hut along the :ieadscrew so as to rotate it and the spindle and thereby to spin the rotor. "in one arrangement the lead screwtis mounted inside a pneumatic cylinder Whose piston slides on longitudinal uides which prevent .its rotation,.andith e driving nut'iis secured or forms part of :thxpistonfisolthat the axial movement of "the pistonhin the cylinder under the pressure of compressed air admitted athereto irotatesgthe lea d screw so Ias' tospin the rotor. To aiiord' a' cornpact arrangement and a suitable velocity ratio, the threaded shaft'iinay conyenientlyiextend alongside and parallel tel-the spindle andi 'be coupled ,i to it'by ste -up gearing. Alternatively, howeyer, -the" lead screw may 'comprise the" outer part of the spindle, the

'2 6 2,8?Zfii22 Patented Feb. 16, 952? retracting means may be made to retract the spindle erte ssriesl Aft r a P eqe e fi d fi 6f femur that: er 1 29119- o ersm e t e e re w emrrae 'set eja b s f h re l i d elit le s ns m mber s ep t ss n Whieh i m e ssssd'w rh th eleres ie h 'e i 5 o assesses; an sr hr' s ei ele me sen 9 wer s r ll 1 ee ere e ew h d r eqs' d t e eta l r; f t Spindle, M Y .Y r bein ss b h ax l e ment to move the locking member into its release posion t eleas t e ee eh fte epr d rm d numb at revelat on o the s indle Se t a w t r r pr n to w hd a t n l he ea eh ma tak e fo m o a bell eeteh capable Qf bein leel ed b an r a l ovabl x r l l k es sleeye surrounding the spindle, the release member may ee sis 2. o thr a nt as exte s ewthresd term e t e p dl t no be n ts p vented iron; rotation but being free to be moved axially along the spindle by the rotation of the spindle to cause it mess g th l k e v an more t e l t e along the spin le into its release position in which it releases h narra s- I in anotherconstruction, the retra ting means may comprisea pneumatic plunger arranged when actuated to withdraw the spindle from the rotor against return spring m ans, for examp e y a t n on one ve of p v ted l ve arlrose othe ens engag s a f a g on the spindle. 'Ilhe plunger may be actuated by causing the pneumatic pistes to rpose a por at pr de e nined poin of its I k? and "thereby to allow compressed 'air topass to ther unsergthro s a ondui -l ading'fro t e p r i-fflgre invention may be carried into practice in yarious ways-.bu,t two specific embodiments will now be described y Way of ex pl ith refer nce to theaecompa y s drawllg, in which:

Figure 1 is aside view, partly sectioned, of a gyroscope asrsflemhly a I Figure -2 is a cross section on the line I,IIIof Figure 1,

Esme 13 is an en yiew of the assembly-of Figure 1, as s ee n in the direction of the arrow -11 ofF-igure 1; and

gEigpre ,4 is a sectional View :of'a modified construction of gyroscope assembly.

in :the embodiment of ;Eigu1:es 1-3 the invention is @Pltlicd to .a gyroscope foriontrolling the flightof a missile xWithin whose ibody ;the gyroscope is mounted;

gyroscope is mounted-in a trame built .into the missiletbody and comprisesiessentially'aIotor 10 mounted Within the frame by means of two 'gimbal rings, namely an inner girnhal ring'll and an .outer ginibal ring 1-2, QQthLof which are capable of pivoting about "axes'which a lertransverse to each ,otherand .transverse'to the'axis-of spiniof {the rotor ill mounted'in :the iinnergimbal ring ll-l. During ,fight the missilewis vcontrolled *bywmeans of an earth reference supplied .;by thegyroscope, which can 'be reoted by the insertion of an instrumentfisuch as a screwdriyer through an aperture in the casing :of the missile intojengagementwith the slotted'ihead i an erecting plunger iii. vIt is important tto' be able to .erectithe gyrosoon {from outside the "missile "and'also to be able .to spin ,the rotor a few minutes before the .missile :is to :be

zr'lihe means provided :for erecting the gyroscope comprises Ira-rotatable erecting plunger 14 provided in .the gyroscope-chasing l5 which 'Callsbf advancedsuccessively into frictional engagement w'ith itwo bevelled -caging rings fiend-1 7 respectively secured to the :t'woTginibH-rings '11 and :12 coaxial ly withtheir pivotal axes. T Theercting pl ger ft tfiis rotated (by'meari's of'a s'crewdriver'applied to a :slot in itsiiead 13) when infcontac t'with the caging ring 17 to rotate the ring and the associated outer gimbal 32 until the plunger encounters a registering gap in the ring 17. The plunger 14 is then advanced further so that it extends through the gap in the ring 17 and so locks the outer gimbal 12 in its erecting position, and the advanced plunger then frictionally engages the bevelled rim of the second caging ring 16. The latter is then rotated by further rotation of the plunger 14 until the plunger engages in a registering gap in the second caging ring 16 to lock the latter and the inner gimbal ring 11 in the erect position. In this way the gyroscope rotor is erected and held in its erect position by the engagement of the plunger 14 in the two registering gaps of the caging rings 16 and 17.

The means for spinning the rotor 10 includes a rotatable telescopic spindle 18 which is formed in two main parts, namely an outer spindle member 19 whose two ends are journalled in bearings 20 and 21 mounted in the frame of the gyroscope casing 15, and an inner spindle member 22 which slides telescopically within the outer member 19 and can be advanced inwardly into engagement with the end of the rotor shaft 23. The whole. spindle 18 is so mounted that it is coaxial with the spin axis of the rotor when the gyroscope is set up in its erect position in the missile, and the retractible inner member 22 of the spindle carries one member 24 of a dog clutch, the other member 25 of which is mounted on the end of the rotor shaft 23 so that the spindle member 22 can be advanced and coupled coaxially to the rotor shaft 23 by means of the dog clutch 24, 25. The dog clutch member 24 is resiliently mounted in the inner spindle member 22 by means of a shock-absorbing compression spring 26 contained in the bore of the spindle member 22.

The inner spindle member 22 is pinned to the outer spindle member 19 by means of a transverse pin 27 which extends right through the inner spindle member 22 near its outer end, the two protruding ends of the pin 27 passing through longitudinal slots 28 in the wall of the overlapping outer spindle member 19. These slots 28 enable the inner spindle member 22 to slide telescopically within the outer member 19, the pin 27 engaging in the slots 28 ensuring that the two spindle members 19 and 22 rotate together as a single torque-transmitting unit 18. The two ends of the transverse pin 27 are secured in a cylindrical ring 29 surrounding the outer spindle member 19 to slide up and down it with the inner spindle member 22.

A helical compression spring 30 is situated between the overlapping portions of the inner and outer spindle members 22 and 19 and bears on flanges 31 and 32 at its two ends so as to tend to retract the inner spindle member 22 telescopically within the outer member 19. A ball catch indicated generally at 33 is provided to hold the inner spindle member 22 in its advanced position engaging the rotor shaft 23, but when the catch 33 is released the return spring 30 retracts the inner spindle member 22 from the rotor shaft 23 to a position in which its tip, bearing the dog clutch member 24, is clear of the space required for rotation of the gimbal rings 11 and 12 relatively to the frame and to the missile. The ball catch 33 is constituted by a number of steel balls 34 each trapped in a hole 35 formed in the sliding cylindrical ring 29, the holes being spaced circumferentially around the ring 29. A corresponding number of correspondingly spaced recesses or dimples 36 are formed around the outer surface of the outer spindle member 19, and the balls 34, which are of larger diameter than the thickness of the ring 29, can be held in locking engagement with these dimples 36 by means of a cylindrical locking sleeve 37 surrounding the sliding ring 29. When the balls 34 are so held by the locking sleeve 37 in engagement with the dimples 36, they prevent the axial movement of the sliding ring 29, and of the inner spindle member 22 secured to it by the transverse pin 27, relatively to the outer spindle member 19. However the locking sleeve 37 is also formed with a series of spaced circumferential holes or recesses 38 into which the balls 34 can move radially outwardly when the locking sleeve 37 is moved axially outwardly along the spindle 18 to its release position. The outward radial movement of the balls 34 into the holes or recesses 38 of the locking sleeve 37 frees the sliding ring 29 and the inner spindle member 22 pinned to it, to allow the return spring 30 to retract the inner spindle member 22 from engagement with the rotor shaft by telescoping it within the outer spindle member 19. A catch biassing compression spring 39 of helical form surrounds the outer spindle member 19 within the locking sleeve 37, and acts between an inturned flange 40 at the inner end of the sleeve 37 and the edge of the sliding ring 29 to bias the locking sleeve 37 out of its release position.

To release the ball catch 33 at a desired moment after the spindle 18 has spun the rotor 10 up to a suitable speed of rotation, a release nut 41 is provided which is threaded on to an external screwthread 42 for-med on the outer spindle member 19, which of course rotates with the inner spindle member 22 as the rotor is being spun. A finger (not shown) projecting from the release nut 41 engages against a fixed abutment surface of a member secured to the gyroscope casing 15 so as to prevent the rotation of the release nut 41 with the spindle 18. The outer spindle member 19 will consequently rotate relatively to the release nut 41 and will thus screw the latter along the co-opcrating screwthreads 42 in the axial direction away from the rotor 10 and towards the locking sleeve 37. When the release nut 41 reaches the locking sleeve 37, further rotation of the spindle 18 will cause the nut 41 to move the sleeve 37, along the spindle 18 against the force of the catch biassing spring 39, until eventually the sleeve 37 reaches its release position in which it releases the ball catch 33 and allows the retraction of the inner spindle member 22 by the return spring 39. The precise number of revolutions of the spindle 18 required to release the ball catch 33 will of course depend on the starting position of the release nut 41 on the screwthreads 42.

To enable the release nut 41 to be moved back towards the starting position, and to enable its starting position to be preset in accordance with the number of revolutions of the spindle required before release, a slot 44 is formed in the head of the outer spindle member at its outer end to receive a screw-driver, by which the whole spindle 18 can be rotated to screw the release nut 41 backwards or forwards on its thread 42. Moreover, the hollow outer spindle member 19 is formed with an aperture 45 at its outer end, enabling a tool such as a \crew-driver or rod to be inserted for pushing the inner s, indle member 22 back into its advanced position in engagement with the rotor shaft 23 against the force of the return spring 30, prior to the locking of the ball catch 33.

A simple pneumatic motor indicated generally at 47 is provided for effecting the rotating of the spindle 18 required to spin the gyroscope rotor 10 up to speed. This motor comprises a cylinder 48 containing a piston 49 which slides on two longitudinal parallel guide rods 50 extending between two end caps 51 and 52 of the cylinder 48 and spaced from the cylinder axis 53. Each guide rod is formed with a head 54 at one end and is screw-threaded at its other end and provided with a clamping nut 55, so that it serves to clamp the two cylinder end caps 51 and 52 to the wall of the cylinder 48. The inner cylinder end cap 51 is formed as a part of the gyroscope casing 15 whilst the outer end cap 52 carries a projecting bracket 56 on which the outer bearing 20 for the spindle 18 is mounted, these various parts being held in their assembled relationship by the clamping action of the guide rods 50, with the cylinder 48 disposed alongside the outer spindle member 19. A rotatable shaft 58 formed with a quick screw-thread 59 extends coaxially through the pneumatic cylinder 48 and is iournalled at its Ewe aszasaa hh n hearin s and stimulated in the aps 52 a d 1- he outerend tthethre, ee'sn prot d s t rough he end an 52 and e the ylinder 48 a ar whee 5,2 A e M whe l 63 having a ma ler numbe of teeth 1. tho te on the outer end of he P.. die member .9 nd. n a s with the se Wh e 62, he two c nstitutin 1, 7 ,11 se r g h b r t t on of the threaded af 5. 5 p Q'- duces correspondingly more rapid rotation of the spi i dle 18 parallel to which the shaft 58 ext nd The piston 49 carries at its central portion a driving nu 6 h c ,is secured to h pis on and is thr e to the quick-threaded shaft 58. Compressed a admitted from an i bo t e carried in th mi sile to one id of h P on. 49 in th y i le 4 to dti the h h along the cylinder, but as rotat on of the piston and of the nut 66 secured to it is prevented by the two guide rods 50, such movement of the piston will cause the rotation of the threaded shaft 58 and thus will transmit a sp i, ing torque to; the rotor via the step-up gearing 62 53 and the spindle 18.

To cushion the piston .49 when it reaches-the end of'its out-ward stroke a resilient sealing pad 67 ,iSinQunted Within the yl nd r a a nst th end ap 5.2-

In practice it has been found that if the .quickthread 59 has a pitch producing about six revolutions of the shaft 58 during he strok of the piston 9 in h outw d d rection d if the step-up gea at o s suit b y ch sen, then it is possible by admission of compressed air at suitable pressure to the inner end of the cylinder to spin the rotor up to a speed of 8,0Q0 revolutions per minute from standstill in /,s of asecond. when the piston approaches the end of its travel the release a ut vftlil will automatically engage the spindle locking sleeve 37 to pause it to v the ball catgh 33, so that the inner end 2 2 of the ,sp dle is then withdrawn clear of the gimhaloperatingl lehying the rotor 10 spinning at the re uired speed.

In the second embodiment of the invention illustrated in Figure 4, the gyroscope rotor 70 is pivotally mounted in bearings 71, 72 in a single gi-mbal ring 73, which is pivoted in the casing 74 of the gyroscope about an axis at right angles to the rotor axis by means of bearings 75 and 76. At one end the gimbal ring 73 is restrained by a torsion bar 77 one end of which is connected to the gimbal shaft 78, and the other end of which carries a head 79 locked in a housing 80 by means of a bolt 81. The other end of the gimbal shaft 78 is connected to a damping disc 82 contained in a damping cup 83 for frictionally damping the rotation of the gimbal ring 73 which is resiliently constrained by the torsion bar '77.

The gyroscope rotor is provided with magnetic inserts 84 in one face which co-operate with stationary electrical pick-off coils (not shown), to provide an electrical pickoif signal which will be a measure both of the rotor speed and of the angular deflection of the gimbal frame 73 against the elastic restoring couple afforded by the torsion bar. Thus, since the component of the rate of turn of the missile or craft in which the gyroscope is mounted, in the plane transverse to the pivotal axis of the gimbal ring 73, will be proportional to the angular deflection of the gimbal ring 73 from its equilibrium position against the elastic restoring couple of the torsion bar, this component of the rate of turn Will be represented by the magnitude of the electrical pick-off signal, for a given rotor speed. The use of magnets carried by a gyroscope rotor for co-operation with separate electrical pick-off coils to provide an electrical pick-off signal is the subject of the present applicants United States of America patent application Serial No. 388,036 (Case No. 311).

In this embodiment the spindle 85 is mounted in bearings 86 and 87 so that it can be rotated coaxially with the rotor shaft. The spindle carries on its inner end a dog clutch member 83 which is slidably mounted on it but is caused to rotate with it by a driving pin 89 whose ends extend into longitudinal slots formed in the member 88.

ports for t e mb l ea n s 5 and T ar s ured, ri he ut r spind e he in 8 s m ted on th Qu 91 .9 can 93 of a p eum ti 'evlih er 94'Whie s elam edt the base P ate 'W'coaxiahv with th pin le by means of two spaced ui e ro 6 nd. h sv ded'wi h e hpng nut 8 a 't r scr w eade m ter 'ehd In his ase the sp dle itse f is ter ed w t a au'ieh hr sd d an Screw h a 9 a d a is ltifl li ah m ted on the guide rods 96 and 97' carries a correspon rrgly cr whr a ed dri n t 01 hich s' hre del Qh the lead screw 99. Qo-mpresst d air is ad bottle th o gh a h l10 03i th. nner nt nal d of the cyl n e 9 dri e the p s n. u w y, hereby t i th spihdlefifi t spi the r t .0 i th 'dc c ut h To disengage the dog clutch when the rotor has been p p i e pivoted o k 10 1s p o ided whi h embraces the sliding 'dog clutch member 38 and engages beneath a flange 105 formed on it. The tailli l of the k 1 4 is en a d y a p eumatic p ihsef 97it 9Y inder 108 formed at the s der one guide 119d .97. The tt is a so fo ith a on itu inal ore 09 umm ng at its ner end withtheiriterigu of the ylh i as e te e d-with Pen s 1, 0 a me fih h s d of th snide f d 5 a a p ih abo thirds along its lengtli Thus when the p is'tonfduring its eutwere st oke e ehes and th let ihe 'ph t ill ch npresse eh s f om i ner end hi 1 1,

yli de 193; t e y cau i, h a ly nd 1 th 'ie k 19 whi 1 h s c ch 8 o o en a e en w th the so.- operating nieaibe 29 a ain th. fes ve o he lieh i-h spring 91, to free the spindle 85 from the spinning rotor 70. As before a buffer pad 111 is provided in the outer end of the cylinder 94 to cushion the piston at the end of its outward stroke, and the exposed outer end of the spindle 85 is slotted at 112 for engagement with a tool such as a screw-driver for the purpose of rotating the spindle to wind the piston 100 back to its inner position in the cylinder 94.

What We claim as our invention and desire to secure by Letters Patent is:

1. Mechanism for spinning a gimbal-mounted gyroscope rotor up to speed which comprises an axially movable rotary clutch member mounted coaxially with the rotor in bearings so positioned as to permit the clutch membar to be advanced into coupling engagement with the rotor, means for rotating the clutch member when so coupled to spin the rotor, the said means comprising a pneumatic cylinder, a lead screw mounted coaxially within the cylinder and having a quick screw thread, a correspondingly threaded driving nut threaded on to the lead screw, a piston slidable in the cylinder and secured to the nut whereby axial movement of the piston in the cylinder ro tates the lead screw, means for preventing the rotation of the nut in the cylinder about the axis of the lead screw, coupling means between the lead screw and the clutch member, the said coupling means transmitting rotation of the lead screw to the clutch member but incorporating a lost-motion sliding connection permitting the axial movement of the clutch member into and out of clutching engagement with the rotor, means for admitting compressed air into the cylinder on one side of the piston to drive the piston along the cylinder to rotate the lead screw and the clutch member with the latter coupled to the rotor, and automatic retraction means acting on the clutch member to retract it from the rotor when the latter has been run up to speed, the retraction means being responsive to the movement of the piston in the cylinder for automatic actuation thereby to retract the clutch member from the rotor on the arrival of the piston at a predetermined point adjacent the end of its stroke in the cylinder.

2. Mechanism as claimed in claim 1 in which the lead screw extends alongside and parallel to the axis of the clutch member, and which includes torque-transmitting gearing coupling the lead screw to the spindle.

3. Mechanism as claimed in claim 2 in which the retracting means for the spindle comprises a catch capable of being locked by a movable locking member in a position in which it holds the end of the clutch engaged coaxially with the rotor against the action of return spring means, and a screwthreaded release member caused to move axially along a co-operating sc'rewthread by relative rotation produced by the rotation of the clutch, such axial movement of the release member being arranged to move the locking member into its release position to release the catch after a predetermined number of revolutions of the clutch, so as to allow the return spring means to retract the clutch from the rotor.

4. Mechanism as claimed in claim 3 in which the catch comprises a ball catch capable of being locked by an i axially movable external locking sleeve surrounding the clutch, and in which the release member comprises a nut threaded onto an external screwthread formed on the clutch, the nut being itself prevented from rotation but free to be moved in the axial direction relatively to the clutch by rotation of the clutch to cause it to engage the locking sleeve and move the latter along the clutch into its release position in which it releases the ball catch.

5. Mechanism as claimed in claim 1 in which the pneumatic cylinder and the lead screw are mounted coaxially with the clutch member, and which includes in thecylinder longitudinal guide rods spaced from the cylinder axis, the piston being slidable on the guide rods but being prevented from rotation about its axis by them.

6. Mechanism as claimed in claim 5 in which the retracting means comprises a pneumatic plunger arranged when actuated to withdraw the clutch from the rotor, and return spring means opposing the action of the plunger.

7. Mechanism as claimed in claim 6 in which the plunger acts on one end of a pivoted lever member whose other end engages a' flange on the clutch, whereby the actuation of the plunger rocks the lever to retract the clutch.

8. Mechanism as claimed in claim 7 including a port which is arranged to be uncovered by the piston at a predetermined point in its stroke and thereby exposed to the compressed air in the cylinder, and a conduit leading from the port to the pneumatic plunger.

9. Mechanism as claimed in claim 8 in which the port is formed in the side wall of one of the guide rods on which the piston slides, the said guide rod being also formed with a longitudinal bore constituting the said conduit.

10. Mechanism as claimed in claim 1 in which the clutch is formed intwo parts which telescope longitudinally one on the other, namely an end portion capable of being extended telescopically from the remaining portion into coupling engagement with the rotor and of being retracted therefrom by the retracting means.

11. Mechanism as claimed in claim 10 including a dog clutch one member of which is carried by the said end portion of the spindle and the cooperating part of which is carried by the rotor.

References Cited in the file of this patent UNITED STATES PATENTS Collins Sept. 9, 1913 

